In a terminal apparatus such as a notebook computer or a smartphone, image data such as a moving image displayed on a display is updated in synchronization with a synchronization signal such as a vertical synchronization signal which is issued at a predetermined time interval. For example, when 60 synchronization signals are issued every second, a processor built in the terminal apparatus generates image data updated every 1/60 seconds. However, when a process of generating the image data is not ended within a predetermined period of time defined as the interval of the synchronization signal, the smoothness in displaying the moving image on the display is impaired. In order to solve such a problem, a method in which an image region on which the image is displayed is divided into a plurality of partial regions, and an image data generating process is performed only for as many number of partial regions with which the image data generating process is ended within a predetermined period of time has been developed. In this method, even when it is difficult to end the image data generating process on all the image regions of the image region within the predetermined period of time, it is possible to generate the image data for a part of the image region within the predetermined period of time, and it is possible to display the generated image data on the display.
As a method of solving a problem caused by the fact that the image data generating process is not ended within the predetermined period of time, a technology in which an image region is divided into a plurality of partial regions, processors are assigned to the respective partial regions, and parallel processing is performed on the partial regions has been known. As related art, there is Japanese Laid-open Patent Publication No. 2011-13852.